1. Field of the Invention
The present invention relates to inertial bullet pullers which are devices utilized to remove the bullet from the casing of cartridge type rounds of ammunition. Inertial bullet pullers operate by first imparting a rapid motion to the cartridge and then bringing the casing thereof to a quick stop. When the casing slows down it tries to slow down the bullet too, thereby imposing tension on the connection between the bullet and the casing. If the tension force is great enough, the connection parts which is the desired result. The tension force is proportional to the time rate of change in the momentum of the bullet and for any given bullet mass is proportional to the time rate of change in bullet velocity. The latter depends on the initial velocity of the bullet and upon the length of time required to stop it, which, in turn, depends on the speed of propagation of the elastic shock wave through the material carrying the cartridge casing.
2. Discussion of the Related Art
Inertial bullet pullers presently in use include a rigid cartridge carrier in the form of a transparent, plastics material tube having an opening at one end adapted to receive a cartridge and provided at its other end with a head portion adapted to be struck against a hard surface. A cartridge support is provided at the one end of the carrier tube for engaging the cannelure or other portion of the cartridge casing. The head end of the carrier tube extends beyond the nose of the bullet and is closed with its interior being tapered at the lower end.
In use, a cartridge is placed in the carrier tube and supported therein by the cartridge support which engages the cannelure. A securing cap is provided for holding the cartridge support to the end of the carrier. The head portion at the end of the carrier tube is repeatedly struck against a hard surface such as the top of a table until the bullet pulls free of the casing. To facilitate both the acceleration of the carrier to a high velocity and the striking of it against a fixed hard surface, the carrier connects to a handle extending transversely from the carrier tube. The resulting carrier and handle combination has the overall shape of a hammer.
These bullet pullers presently employ cartridge supports in the form of an open-sided washer which extends from the top of the cartridge carrier to underneath the upper side of the cannelure when the puller is in use. A snug-fitting polyethylene cap is slipped over the upper end of the carrier and frictionally engages the carrier tube and holds the washer and cartridge in place. Such a cartridge support is the source of some difficulty because a plurality of support washers having differing inner diameters must be employed in order to accommodate cartridges having different diameter cannelures. Also, after each use it is necessary to pull the tight-fitting cap off the end of the carrier.
Another form of cartridge support employed by currently available bullet pullers consists of a U-shaped plate which has a variable width between its tines in order to adapt it to cannelures of different diameters. However, such a cartridge support has so little area of engagement with the cannelure that it readily shears if the carrier is struck too hard.
An improvement over the above inertial bullet pullers is disclosed in my U.S. Pat. No. 3,646,661. According to my inertial bullet puller, an annular segmented support is provided at the upper end of the carrier of the bullet puller which is extendable into and retractable from the cannelure of a cartridge placed therein. Additionally, the annular segmented support is configured to fit a wide range of cartridges having cannelures of different diameters. The annular segmented support comprises a plurality of arcuate shape members or segments adapted to be annularly disposed at the upper end of a carrier. A garter spring extends around the segments to provide a resilient force for urging the segments radially inwardly to an extent limited either by engagement with a cartridge or by the otherwise spaced apart sides of the segments coming into engagement. A cam surface is provided for positively urging the segments radially inwardly and holding them positioned beneath the upper wall of a cartridge cannelure. The cam surface is carried by a cap that threadably engages the upper end of the carrier tube adjacent the cannelure.
Although the inertial bullet puller disclosed in my U.S. Pat. No. 3,646,661 improves over existing inertial bullet pullers, it fails to operate as easily and efficiently as desired. That is, once the bullet disengages from the case, it is necessary to remove the securing cap before the bullet may be retrieved from the carrier tube. Although the cartridge support was originally intended to part sufficiently far enough to allow the bullet to pass, it was discovered that no matter how much the carrier tube is shaken or the securing cap rapped against a hard surface, the bullet will not pass and cannot be removed without first removing the securing cap. Thus, the use of the inertial bullet puller disclosed in my U.S. Pat. No. 3,646,661 is both tedious and requires a notable time investment when a significant number of bullets are disengaged from their casings. Such performance characteristics are less than desirable to the ordinary shooting enthusiast.
An improvement over the inertial bullet puller disclosed in my U.S. Pat. No. 3,646,661 is disclosed in my allowed U.S. patent application Ser. No. 07/967,214. That inertial bullet puller improves over standard inertial bullet pullers including my U.S. Pat. No. 3,646,661 by employing a redesigned annular segmented support. A first design of the annular segmented support comprises three segments connected together using a flexible O-ring. The O-ring is permanently affixed to the three segments and then severed at one spot so that it no longer forms a continuous ring. The O-ring is permanently affixed to the plurality of segments in order to keep them all connected together, however, it is split to prevent the segments from being continuously forced radially inward.
The second design comprises two segments, the ends of which are shaved so that they protrude less than the center. For use with rifle cartridges, the two segments are connected together with an O-ring, but for use with pistol cartridges, the O-ring is removed and the two segments are left unconnected. The segment ends are shaved so that uniform pressure in a radially inward direction will be applied to the segment centers by the securing cap as it is threadably attached to the carrier tube. A uniform pressure is necessary to ensure that the segments move squarely as they engage the casing cannelure. Square and uniform movement of the two segments as they engage the casing cannelure allows them to grasp the cannelure along the greatest surface area. If the ends of the segments were not reduced, the segments would engage the cannelure only at their ends, thereby permitting many of the cartridges to pass through the segments after the carrier tube was struck against a hard surface.
Both designs improve over the above-described inertial bullet pullers because they permit the bullet to be extracted after separation from the casing without first having to remove the securing cap attached to the upper end of the carrier tube. The first design allows passage of the bullet because the segment ends which remain unconnected as a result of the severed O-ring open sufficiently far to allow the bullet to pass when the carrier tube is shaken or the securing cap is rapped against a hard surface. Similarly, the second design allows passage of the bullet because due to the use of only two segments there will always be an opening between the two segments, even in their most closed position, which is sufficiently large to allow the bullet to pass when the carrier tube is shaken or the securing cap is rapped against a hard surface.